It is known that conventional water-proof, fuse-bonding fabric can be produced by coating at least one surface of a fabric, for example, a woven canvas, with a synthetic resin, such as polyvinyl chloride, which is capable revealing the sn adhering activity when a high frequency wave treatment or heat treatment is applied thereto. However, the above-mentioned conventional water-proof, fuse-bonding fabric has the following disadvantages.
1. Since the specific gravity of the synthetic resin, such as polyvinyl chloride, is high, the resultant water-proof fabric is very heavy.
2. Since the synthetic resin forms a continuous non air-permeable layer on the surface of the fabric, the resultant water-proof fabric is not air-permeable.
The former disadvantage can be eliminated by replacing the synthetic resin, such as polyvinyl chloride, having a high specific gravity with another synthetic resin, for example, acrylic resin and chloro-sulfonated polyethylene, having a low specific gravity. However, these low specific gravity synthetic resins are not capable of providing adhering activity even when the high frequency treatment or heating treatment is applied thereto.
The latter disadvantage can be eliminated by impregnating the fabric with an air-permeable water-proofing agent, for example, paraffin, metallic soap, zirconium compound or silicone. In this case, it is preferable that the fabric to be water-proofed comprise cellulose fibers, for example, cotton, linen or rayon. This type of air-permeable, water-proof celullose fiber fabric is suitable for various covering sheets, for example, hoods of trucks and boats, which are required to be highly air-permeable. If the covering sheet is not air-permeable, a reduction in the atmospheric temperature will cause moisture in a space covered by the covering sheet to be condensed so as to form water drops on the lower surface of the covering sheet, and then, the condensed water drops to fall down and wet articles under the covering sheet. However, the conventional air-permeable, water-proof fabric cannot be fuse-bonded by applying the high frequency wave treatment or the heating treatment thereto.
The fuse-bonding operation for the water-proof fabric is simpler and easier to perform than the conventional operation for sewing. Accordingly, it is desirable to provide a water-proof fabric which is capable of fuse-bonding by applying the high frequency wave treatment or heating treatment thereto, in spite of the fact that the water-proof fabric has been impregnated with an air-permeable water proofing agent or coated with a synthetic resin not capable of fuse-bonding.